The recent few years has witnessed an explosive growth of Internet traffic in networks, particularly in cellular wireless networks. This growth has been fueled by a number of new developments that includes faster, smarter, and more intuitive mobile devices such as the popular iPhone® series and the iPad® series, as well as faster wireless and cellular network technologies that deliver throughputs on par or better than fixed line broadband technologies. For many people today, a primary mode of access to the Internet is via mobile devices using cellular wireless networks. Users have come to expect the same or similar quality of experience as in fixed line broadband networks.
In general, cellular wireless networks have higher random packet loss and longer round trip time (RTT) than fixed line networks mainly because of versatile radio characteristics and restrictive data rates and bandwidths. Characterizing behavior and performance of mobile data services offered by cellular wireless networks is a challenging undertaking. The multitude of technologies (e.g., GPRS, CDMA, UMTS, and LTE), generations (e.g., 2.5G, 3G, and 4G), variations (EDGE, EVDO, HSPA, LTE-A), and mobile terminal classes, in conjunction with different requirements of various applications (e.g., web browsing, large file downloads, video streaming, and real-time communications) result in an enormous number of combinations and a highly variable and mixed environment.
Rapid growth of data traffic naturally has caused high congestion, and this congestion has resulted in losses and/or transmission delays of data packets over the air. Network operators have endeavored to develop various traffic management techniques to control explosive data traffic and to increase throughput on their systems, thereby providing satisfactory quality of service to their clients. Traffic management is a broad concept and includes techniques, such as directing certain classes of traffic to an optimization service, blocking or time shifting certain types of traffic, handling traffic under certain congestion situations, and so on.
In particular, optimizing traffic in congestion situations is one of many components in the array of traffic management techniques used by wireless network operators. Congestion control of data traffic can be performed in a transport layer. Transport layer congestion handlers are generally classified into two main categories: loss-based and delay-based.